<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Document</title>
</head>
<body>
  <script>
    var obj = {foo:123}
	console.log(obj)
	setTimeout(function() {
		obj.foo = 456
		console.log(obj)
	}, 3000)
  </script>
</body>
</html>
